Fluorochemical compounds are well known and commercially used to render various substrates oil- and water repellent and to provide other desirable properties thereto such as soil repellency and soil release. For example, U.S. Pat. Nos. 5,292,796 and 5,453,540 disclose certain fluorochemical oligomers for the treatment of substrates such as, for example, fibrous substrates. The oligomers disclosed are typically functionalised with an isocyanate group to cause reaction with the fibrous substrate surface.
Fluorochemical compounds including silanes are also known and commercially available. For example, FC 405 is a fluorochemical silane that is commercially available from 3M Company for rendering substrates such as glass or ceramics oil and water repellent. However, this product is solvent based and it would be desirable to have water based product for treating such substrates as glass or ceramics.
U.S. Pat. No. 5,980,992 discloses the use of fluorochemical silanes for the treatment of silicon-containing organic polymeric surfaces to restore the repellency thereof. The repellency of silicon-containing organic polymeric surfaces that become spent during use can be restored by treatment with fluorinated silane containing compositions. These compositions are however applied from solvent.
Fluorochemical compounds that can be applied from water are also known in the art. For example, U.S. Pat. No. 5,274,159 discloses a fluorochemical silane having hydrolysable polyoxyalkylene groups bonded to the silicone atom of the silyl groups. These groups are taught to hydrolyse in the presence of an acid or base catalyst after application to a substrate. However, the obtained oil- and water-repellency properties of the coated substrate and abrasion resistance leave room for further improvement.
Still further aqueous based fluorochemical compositions are disclosed in U.S. Pat. No. 5,550,184 and WO 99/29636. U.S. Pat. No. 5,550,184 discloses a hydrolysed silane emulsion obtained by emulsifying a hydrolysable perfluoroalkoxysilane in water in the presence of an emulsifier. WO 99/29636 discloses aqueous emulsions containing 1) a fluorocarbon silane hydrolysate generated in the presence of a surfactant and 2) a silicate, which provides a clear and smooth coated surface having water repellency and heat resistance when applied to a substrate.
Despite the many known fluorochemical compositions for the treatment of surfaces, there continues to be a desire to find further beneficial fluorochemical compositions and in particular fluorochemical compositions for the treatment of hard surfaces that can be applied in an environmental friendly way from an aqueous based composition. Preferably, such fluorochemical composition will have a high water repellency, high oil repellency and preferably have a high durability. Further desired properties are good stain resistance and/or stain release. Desirably, the compositions are easy to manufacture in a cost effective and convenient way.